Electric switch



Dec. 27, 1932. .1. c. STEARNS I 7 5 ELECTRIC SWITCH I Filed June 20 1930 Gavan 6T cf'zearw 46y www Patented Dec. 27, 1932 PATENT OFFICE JASON C. STEARNS, 0F WORCESTER, MASSACHUSETTS ELECTRIC SWITCH Application filed June 20,

This invention relates to an electric switch, especially designed for use on low-voltage circuits, such as automobile lighting systems and the like.

The principal objects of the invention are to provide a switch having sliding contact of a very flexible nature in which the operating handle is not rigidly mounted on a pivot pin but is free to swing on an axis without such rigidity; in which the spring for holding the movable contact member in engagement with the terminals of the circuit also holds the handle back in a socket so that the handle will be pivotally mounted with spring-pressure behind. it, and yet capable of moving bodily away from its pivot support; and to provide a contacting member connected with the operating handle flexibly, so that it can move in an irregular or curved path without binding any of the parts, and so constructed that it will operate effectively over two contacts in different planes, making a sliding contact with both, thus insuring the keeping of the contacts clean.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is a side view of a switch constructed in accordance with this invention;

Fig. 2 is a plan of the same;

Fig. 3 is a bottom plan;

Fig. 4 is a sectional view on the line 4-4 5 of Fig. 2, showing the parts in the connected position;

Fig. 5 is a sectional view on the line fr-5 of Fig. i;

Fig. 6 is a view of the operating surface ofthe movable contact member;

Fig. 7 is an edge view of the same;

Fig. 8 is a rear view thereof, and

Fig. 9 is a side view of the switch with the front wall removed. showing the parts in the disconnected position.

I have shown this switch constructed in a very simple form suitable for use on automobiles. and involving a sheet metal casing 10, an insulating bottom 11, a pair of metal brackets 12 on the bottom provided with screws 13 for holding the terminals 14, and

1930. Serial in. 462,650.

an operating handle 15 supported by the metal casing 10.

(in the insulating bottom ll are two contacts i6 and 17. The contact 16 is merely a rivet-head provided with a liat surface and constituting a part of the rivet 18 which extends through the insulating bottom 11 and the bracket 12. It holds the bracket- 12 mechanically and of course connects it with the contact 16 electrically.

The contact 17 is held by a similar rivet 19 and connected with the other bracket 12 thereby. This contact 17 is'a plate having an angular projection 20, preferably extending all the way across it, and obviously extending beyond the plane of the head or contact 16. These two contacts are, of course, connected \viththe terminals of the line and insulated fully from each other. i

The casing 10 is preferably made of a single piece of sheet metal having sides and ends and a top 21. This top is in the form of a plate integralwith the casing and having two ears provided with perforatirms 22 for receiving screws or other fastening devices to secure it on the panel board or elsewhere as desired. This plate is provided with a central perforation having annular walls 23 constituting the segment of a sphere and having spherical arcuate bearing surfaces on the inside.

Extending through thecentral opening in. the top 21 is the handle 15. This is axially hollow and provided with a spring 25 and a plunger 26. It also has a spherical bearing fitting in the bearing surface 23. The plunger 26 has a spherical end 28. It will be seen that when this spherical end is pressed against some object by the spring 25 the spring also forces the handle outwardly and the spherical bearing against the bearing surface 23. Therefore, as will be seen later, one

of these surfaces is pressed against the other constantly by spring pressure.

The other member of the device is the con- 5 tact member 30 made, of course. of metal and in the form preferably of a small square plate with two cars 31 projecting up through slots or notches 32 in an insulating plate 33 on opposite sides so as to hold the contacting plate 30 thereon. This insulating plate 33 is provided with an oblong recess 34 in the back for receiving the spherical head 28, and the insulation is maintained by an insulating plate 35 which may be a part of the plate 33 and is so considere From a comparison of Figs. 4 and 9, it will be seen that the handle 15 can be moved back and forth, and in one position (Fig. 4) it completes the circuit by means of the metallic plate which rests at one edge on the contact 20. In the off position it rests on the contact 20 and the head of the rivet 19.

It will be seen that this plate 33 has to traverse a double curve or sloping path to go from one position to the other. In doing so the comparatively sharp edge of the contact 20 will wear on the surface of the plate 30 and keep it clean. The irregularity of movement of the member 33 is fully taken care of by the spring 25 which always presses the contact plate 30 toward the contacts 16 and 20 and also presses the handle outwardly, which keeps the spherical surface 27 always spring-pressed to its seat. Thus an easy working spring held device is secured in which the contacts will always be clean and c the parts are few and simple and very easily manufactured and assembled. The single spring required is entirely enclosed and 1naccessible to dirt and dust. This switch is especially adaptable for use on low voltage circuits such as are used with the lighting systems of automobiles.

Although I have illustrated and described 'only a single form of the invention I am aware of the fact that changes can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the exact form the sp erical portion against the annular bearing, a flat insulating plate having a recess in which the spherical end of the plunger fits, a flat contact plate carried by said insulating member, and a air of separated contacts one of which is of projecting V-shape and so located that the flat contact plate can be moved by the handle and plunger over it, to cause the flat plate to rock about the V- shaped contact as a fulcrum.

2. In an electric switch, the combination of a casing having an annular bearin a handle having a portion fitting and turnin in said bearing, a plunger on the inner en of the handle, a spring in the handle tending to force the plunger outwardly and the spherical portion against the annular bearin a fiat insulating plate having a recess in w oh the end of the plunger fits, a fiat contact plate carried by said insulating member, and a 

